Since damaged ACL's (anterior cruciate ligaments) are so common, I wanted to expand a little on this situation in addition to the previous posts. A recent article in one of our journals, the
Clinician's Brief by Dr. James Roush at Kansas State clarified some important points.
Medical journals refer to this problem as CCLR (cranial...same as anterior...cruciate ligament rupture), so that's what we will call it too. It is the most common cause of hind leg lameness in the hunting dog. If the torn cruciate in not repaired, permanent arthritis in the joint can occur.
There are some studies that show a genetic component of CCLR. While all dogs are at risk, larger active dogs have a higher incidence. It is unusual for a puppy to have this problem because their bones are still quite flexible. As a dog ages and his/her bones become more stiff, a sharp twisting of the knee (called the stifle) is more likely to put stress on the knee ligaments. There have been some researchers that think a mild bacterial infection may have a role in weakening the ligament. If a dog ruptures a ligament in one knee it often does the same thing in the opposite knee at a later time.
Typically, a dog with CCLR will be acutely lame for several days, get better, then become really lame in about a month. In our practice, we see both legs affected in about 20% of the dogs with CCLR.
Your veterinarian can diagnose the condition by manipulating the joint checking for abnormal movement or a firm swelling on the inside of the leg near the joint.
Treatment for CCLR is surgical. In studies done, 81% to 100% of large hunting type dogs will remain lame unless surgical correction is done. There are numerous surgical techniques for correction but they can all be broadly lumped into "outside the joint capsule" and "inside the joint capsule". In our practice, we only do the "outside" procedures. Typically, an implant of some sort, usually a very heavy nylon thread is used to stablize the joint. In the hands of more advanced surgeons, a procedue called a "TPLO" is currently the gold standard for CCLR correction. While the TPLO is considered the best procedure, some studies have shown no difference in long-term results using the "outside the joint" techniques versus TPLO or a newer surgery called a "TTA". Regardless, your veterinarian can guide you on the availabilty of TPLO/TTA procedures and their value compared to the "outside the joint" surgeries.
After any joint surgery, physical activity must be decreased for at least 8 weeks. Physical therapy for hunting dogs with CCLR repair has advantages because this therapy may get the dog back in the field quicker. Weight loss is also a part of the aftercare, even to the point of being a bit thin. Most dogs will be weight bearing on the surgery limb in less than a week and regain near normal gait within 6 weeks but total healing often takes up to 6 months.
The prognosis for CCLR repair is excellent with >90% of these dogs returning to normal function after surgery.
There is no known way to prevent
CCLR except keeping your dog at an optimal weight, i.e. no overweight dogs.